NEW YORK -- NATO Secretary-General Anders Fogh Rasmussen has said he is "very encouraged" by talks on cooperation held between Russia and NATO member states on the sidelines of a major UN summit in New York.

"They were in the right spirit, they addressed the right issues, and they made it clear that we truly are on a solid path now to improve NATO-Russia relations," he said.

Rasmussen expressed hope that Moscow and NATO will step up cooperation on conventional arms control and missile defense before the NATO leaders' summit in Lisbon this November.

In a possible sign that it has objections to further cooperation, Moscow has not yet said it will attend.

The NATO secretary-general said more than two dozen ministers had expressed a desire at the September 22 meeting of the NATO-Russia Council to take substantial steps that will move cooperation forward with a focus on the practical and pragmatic.

"Stepping up our joint support for Afghanistan and our shared fight against narcotics, fighting terrorism, fighting piracy; we discussed how to continue to build security within Europe," Rasmussen said.

Clinton: U.S., Russia 'Not Adversaries'

Earlier, U.S. Secretary of State Hillary Clinton -- who attended the meeting -- strongly endorsed NATO plans to build cooperation with Russia on missile defense, saying the alliance should endorse a plan by November to resume missile-defense exercises and explore ways to link early warning systems.

"In the longer term, NATO and Russia should work together to develop models for a combined NATO-Russia missile defense architecture," Clinton said.

She told her Russian counterpart, Foreign Minister Sergei Lavrov, "The United States does not believe that NATO and Russia are adversaries, indeed, the opposite is true." Clinton said missile defense, stemming the flow of narcotics from Central Asia, and conventional forces in Europe were areas of shared interest between the two countries.

In that vein, Clinton urged revival of a Cold War-era treaty -- the Conventional Forces in Europe treaty -- which sets limits on troops and weapons. But she rejected the idea of a new security architecture in Europe, which was first proposed by President Dmitry Medvedev last year.

Defense Secretary Robert Gates had much the same message when he met with his counterpart, Russian Defense Minister Anatoly Serdyukov, last week in Washington. Those talks ended with Serdyukov agreeing to continue talks on missile defense and both agreed to try to resume talks on conventional forces.

Rasmussen said cooperation between NATO and Russia on missile defense should be accelerated even though sticking points remain, such as the situation in Georgia and Moldova, on which Russia and NATO fundamentally disagree.

Although no technical discussions have been held on missile defense cooperation with Russia, Rasmussen said NATO is considering expanding so-called "theater missile defense" to "territorial missile defense," a step he said would provide protection to deployed troops as well as civilian populations.

"If we do so, I think it makes sense to invite Russia to cooperate, also when it comes to territorial missile defense. And then, of course, there are a lot of technical details to be elaborated and we will do that in the next phase," he said.

The draft proposal for the new NATO strategy, which will be discussed in Lisbon, closely resembles the UN charter. The similarity has triggered speculation that NATO could replace the UN in international peacekeeping operations.

Rasmussen flatly rejected that idea, saying "NATO has no intention of replacing the United Nations."